Hemispheric differences in the control of limb dynamics: a link between arm performance asymmetries and arm selection patterns.
Level 4 - case-series / case-control
Non-clinical laboratory behavioral and biomechanical experiment in healthy volunteers (graded by design analogy).
PubMed 23155169 · doi:10.1152/jn.00885.2012
What was done
Right-handed participants completed choice and nonchoice reaching movements to eight radially arranged targets (3.5 cm diameter, 13 cm radius) from a midline starting position. Visual feedback cursors for each hand were displaced 30 cm to the midline to remove geometric, mechanical, and perceptual biases for midline targets. Hand path trajectories, arm selection patterns, and inverse dynamics were measured.
What was found
The abstract reports no numerical values, variances, or statistical test results. Lateral targets were predominantly reached using the ipsilateral arm (hemispace bias). Midline targets equidistant from both hands were selected more frequently with the dominant arm. Hand paths for dominant arm reaches to midline targets were straighter and more accurately directed, with inverse dynamics revealing greater exploitation of intersegmental dynamics than the nondominant arm.
Why it matters
This study provides evidence linking arm selection preferences to hemispheric asymmetries in limb dynamic coordination, suggesting motor choice is driven by underlying sensorimotor proficiency.
Limits
The abstract omits sample size, participant demographics, and quantitative effect sizes. The study evaluated only right-handed individuals under constrained laboratory planar reaching conditions with artificial visual cursor displacements.
Cited by
- context A person's limb with greater gross force or strength is typically not the limb used for fine motor neural control.